It's a deceptively dangerous business, this job of fighting fires.  There's the heat, of course. The dangers of floors and ceilings collapsing, of steam burns from too much water in the wrong place at the wrong time, the dreaded flash-overs that give an attentive firefighter perhaps three seconds to escape the inferno that follows.  But those are the  visible hazards, the gross aspects of a multidimensional assault on the human body. It's when the invisible poisons begin to work that firefighters need help the most -- and until the state steps in to lend a hand, Pennsylvania's firefighters have only each other to rely on.